287 research outputs found

    Challenges faced by science teachers in continuing & distance education

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    Este estudo investigou as características pessoais, as preocupações, os desafios do processo\ud de estudo e os investimentos (esforços) de um grupo de professores de ciências que participou, com sucesso, de cursos de formação contínua a distância (FCD) em uma universidade pública. Os dados foram coletados por meio de entrevistas e analisados qualitativamente com a utilização de códigos e descritores. Autonomia, motivação, disciplina e responsabilidade foram algumas características pessoais encontradas nesta pesquisa. Preocupações relacionadas às exigências da formação, às expectativas em relação ao sucesso no curso, ao processo de interação, aos conhecimentos adquiridos e às tecnologias foram catalogadas. Os maiores desafios enfrentados pelos professores para conduzir, de forma satisfatória, o processo de estudo a distância estão relacionados com a organização, a disciplina e a autonomia. Os resultados mostraram, por fim, que são necessários investimentos intelectuais e emocionais para participar desse tipo de formação. Esses dados podem auxiliar os formadores na gestão do curso, assessorando os professores ao longo da FDC e potencializando suas aprendizagens.This study examines the personal characteristics, the current concerns, and the challenges\ud of academic study. In addition, it examines the investment (efforts) of science teachers who\ud participated in distance continuing education courses (DCEC) within a public university. Data\ud were collected from interviews and then analyzed qualitatively using codes and descriptors.\ud Autonomy, motivation, discipline and responsibility were some of the key characteristics of\ud the teachers evaluated in this study. Concerns regarding training needs, students’ expectations with regard to their success in the course, the interaction process, the acquired skills, and the\ud technologies used, were identified and later recorded on paper. The greatest challenges faced\ud by professors in successfully managing the distance education process were related to personal\ud study skills (organization), personal discipline, and autonomy. Finally, the results show that\ud intellectual and emotional effort is required to participate in this type of online training.\ud Furthermore, the findings from this study may facilitate course management trainers, thereby\ud assisting DCEC professors during the entire learning process, and maximize the potential of\ud science education

    A Solar-Powered Fertigation System based on Low-Cost Wireless Sensor Network Remotely Controlled by Farmer for Irrigation Cycles and Crops Growth Optimization

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    Nowadays, the technological innovations affect all human activities; also the agriculture field heavily benefits of technologies as informatics, electronic, telecommunication, allowing huge improvements of productivity and resources exploitation. This manuscript presents an innovative low cost fertigation system for assisting the cultures by using data-processing electronic boards and wireless sensors network (WSN) connected to a remote software platform. The proposed system receives information related to air and soil parameters, by a custom solar-powered WSN. A control unit elaborates the acquired data by using dynamic agronomic models implemented on a cloud platform, for optimizing the amount and typology of fertilizers as well as the irrigations frequency, as function also of weather forecasts got by on-line weather service

    A Solar-Powered Fertigation System based on Low-Cost Wireless Sensor Network Remotely Controlled by Farmer for Irrigation Cycles and Crops Growth Optimization

    Get PDF
    Nowadays, the technological innovations affect all human activities; also the agriculture field heavily benefits of technologies as informatics, electronic, telecommunication, allowing huge improvements of productivity and resources exploitation. This manuscript presents an innovative low cost fertigation system for assisting the cultures by using data-processing electronic boards and wireless sensors network (WSN) connected to a remote software platform. The proposed system receives information related to air and soil parameters, by a custom solar-powered WSN. A control unit elaborates the acquired data by using dynamic agronomic models implemented on a cloud platform, for optimizing the amount and typology of fertilizers as well as the irrigations frequency, as function also of weather forecasts got by on-line weather service

    Acyl-coenzyme a:Cholesterol Acyltransferase Promotes Oxidized LDL/Oxysterol-Induced Apoptosis in Macrophages

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    7-Ketocholesterol (7KC) is a cytotoxic component of oxidized low density lipoproteins (OxLDLs) and induces apoptosis in macrophages by a mechanism involving the activation of cytosolic phospholipase A2 (cPLA 2). In the current study, we examined the role of ACAT in 7KC-induced and OxLDL-induced apoptosis in murine macrophages. An ACAT inhibitor, Sandoz 58-035, suppressed 7KC-induced apoptosis in P388D1 cells and both 7KC-induced and OxLDL-induced apoptosis in mouse peritoneal macrophages (MPMs). Furthermore, compared with wild-type MPMs, ACAT-1-deficient MPMs demonstrated significant resistance to both 7KC-induced and OxLDL-induced apoptosis. Macrophages treated with 7KC accumulated ACAT-derived [14C]cholesteryl and [ 3H]7-ketocholesteryl esters. Tandem LC-MS revealed that the 7KC esters contained primarily saturated and monounsaturated fatty acids. An inhibitor of CPLA2, arachidonyl trifluoromethyl ketone, prevented the accumulation of 7KC esters and inhibited 7KC-induced apoptosis in P388B1 cells. The decrease in 7KC ester accumulation produced by the inhibition of cPLA 2 was reversed by supplementing with either oleic or arachidonic acid (AA); however, only AA supplementation restored the induction of apoptosis by 7KC. These results suggest that 7KC not only initiates the apoptosis pathway by activating cPLA2, as we have reported previously, but also participates in the downstream signaling pathway when esterified by ACAT to form 7KC-arachidonate

    Genesis and mechanisms controlling tornillo seismo-volcanic events in volcanic areas

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    Volcanic activity is often preceded or accompanied by different types of seismo-volcanic signals. Among these signals, the so-called tornillo (Spanish for "screw") events are considered to belong to a unique class of volcano-seismicity characterised by a long-duration coda, amplitude modulation and high-quality factor. These data constitute important evidence for the gas fraction inside magmatic fluids. However, the mechanism behind this unique signal remains not fully understood. Here we report new laboratory evidence showing that two different processes have either scale-invariant or scale-dependent effects in generating tornillo-like events. These processes are respectively the gas pressure gradient, which triggers the event and regulates the slow decaying coda, and the fluid resonance into small scale structures which, in turn, control the frequency content of the signal. Considering that the gas pressure gradient is proportional to the fluid flow, these new findings, as applied to volcanoes, provide new information to better quantify both gas rate and volume, and the dimension of the resonator.Publishedid 73385V. Processi eruttivi e post-eruttiviJCR Journa
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